GATE Exam Questions

1

Group symbols assigned to silty sand and clayey sand are respectively

A. SS and CS
B. SM and CS
C. SM and SC
D. MS and CS

2

In a BOD test using 5% dilution of the sample (15 ML of sample and 285 mL of dilution water), dissolved oxygen values for the sample and dilution water blank bottles after five days incubation at `20^circ`C were 3.80 and 8.80 mg/L. respectively. Dissolved oxygen originally present in the undiluted sample was 0.80 mg/L. The 5-day `20^circ`C BOD of the sample is

A. 116 mg/L
B. 108 mg/L
C. 100 mg/L
D. 92 Mg/L

3

A footing 2 m x 1 m exerts a uniform pressure of 150 kN/m2 on the soil. Assuming a load dispersion of 2 vertical to 1 horizontal the average vertical stress (kN/m2) at 1.0 m below the footing is

A. 50
B. 75
C. 80
D. 100

4

Two completely penetrating wells are located L (in metres) apart, in homogeneous confined aquifer. The drawdown measured at the mid point between the two wells (at a distance of 0.5 L from both the wells) is 2.0 m when only the first well is being pumped at the steady rate of Q1 m3/sec. When both the wells are being pumped at identical steady rate of Q2 m3/sec, the drawdown measured at the same location is 8, 0 m. It may be assumed that the drawdown at the wells always remains at 10.0 m when being pumped and the radius of influence is larger than 0.5 L Q1/Q2 is equal to


A. 8/5
B. 4/3
C. 5/8
D. (L/2)

5

Flow at critical depth takes place in an open channel When

A. for a given specific energy, discharge is maximum
B. for a given discharge, specific energy is maximum
C. discharge is minimum for a given specific energy
D. discharge is maximum for a given specific force